It isn't the best in non sandstorm teams, but it is actually a pretty dang good support in teams that synergize with it(aka sandstorm teams). It can set sandstorm, and with All Aboard! in sandstorm give free move next to every sync pair(in addition it also boosts crit rate and attack). It can heal with Potion, raise both attack stats by 2 the first time it uses sandstorm, get both defenses boosted in sandstorm, and can even lower opponents accuracy and boost speed when it uses mud slap in sandstorm. Long story short, even without grid, it can do amazing support for sandstorm teams. With grid, it is even better but provided with a sandstorm offense unit(Cynthia and Garchomp, Blue and Aerodactyl, but with grid, Emmet and Archeops, etc)it can cause some havoc.
Source: https://gamepress.gg/pokemonmasters/pokemon/ingo-excadrill
